An optimal application framework enables a mobile equipment real-time software developer to focus and spend development time adding application-related value to a product while still having the flexibility to achieve real-time performance. However, developers of real-time application software are often required to spend an inordinate amount of time writing code that only serves the purpose of supporting actual application-related functionality (i.e., so-called plumbing code) for new software applications. In addition, writing this lower-level plumbing code is usually considered to be more error-prone than writing higher level application software.
Most existing frameworks offer an environment that is either too generic or too restricted. Most frameworks are too generic in the sense that they offer only low-level services that are similar to primitives supported by most operating systems (OS) and that offer considerable flexibility but also require generation of considerable plumbing code.
Other frameworks are too restricted in terms of flexibility in that they: 1) offer limited possibilities to dynamically add new functionality to the framework or scale away code or functionality not needed; 2) do not offer multithreading capabilities; or 3) support only one event notification model (e.g., message (event pull) or callback (event push), but not both). In addition, most frameworks do not address legacy problems that are created when a developer ports previous investments in code to a new framework. Many of the legacy problems listed above arise from a structural mismatch (e.g., different OS paradigms) between an old system and the framework to which the code is to be ported.
By eliminating any unnecessary (e.g., OS specific) paradigm-related functionality and offering clean abstract support for existing basic paradigms, the porting work is facilitated. From an application programmers' perspective, it would thus be desirable to maximize a ratio between application code and necessary, but from an application developer's point of view, unproductive support code.
At present, several frameworks exist that export similar services to applications (e.g., PalmOS, Brew). Existing frameworks differ not only in terms of underlying support mechanisms (e.g., single/multi-threading), paradigms (e.g., function-based/object-oriented), but also with respect to a level of support and flexibility offered to applications. However, many frameworks do not provide a high-level application-domain environment, but instead merely allow a system to be divided into low-level processes, etc. . . . , in a similar fashion to a standard operating system. The application developer is thus left to either include standard functionality in the application code or develop in-house high-level application support.